The present invention relates to fireplaces. It is now quite common to provide a fireplace with a prefabricated combustion chamber that is intended to be connected to a flue. These fireplaces may either be inserted into existing conventional masonry fireplaces or may be installed and subsequently framed within the structure of the building. The heating and visual effects of the fireplace are conventionally supplied by means of a gas burner which simulates a conventional wood fire.
In order to retain the visual appeal of the fire, it is necessary for the combustion conditions to be carefully controlled and, more significantly, for safety purposes it is necessary to ensure that combustion products from the burner are conveyed to the flue. For this reason, it is usual to provide a supply of air to the flue to ensure that there is a constant flow of air along the flue that will induce the flow combustion products from the combustion chamber and into the flue and also to dilute the combustion products to reduce condensation in the flue.
Because of the importance of the air flow through the flue, it is now considered a requirement to provide for verification of the air flow after the unit has been installed. Conventionally, the balance flue has been provided from the front of the appliance but in order to maximize the viewing area of the combustion chamber, it has been proposed to provide the balance flue solely from the rear. However, where the appliance is to be located in a recess, this prevents testing of the balance flow to ensure that the flue has not been blocked.